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authorVladimir Makarov <vmakarov@redhat.com>2016-01-29 18:47:17 +0000
committerVladimir Makarov <vmakarov@gcc.gnu.org>2016-01-29 18:47:17 +0000
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re PR target/69299 (-mavx performance degradation with r232088)
2016-01-29 Vladimir Makarov <vmakarov@redhat.com> PR target/69299 * config/i386/constraints.md (Bm): Describe as special memory constraint. * doc/md.texi (DEFINE_SPECIAL_MEMORY_CONSTRAINT): Describe it. * genoutput.c (main): Process DEFINE_SPECIAL_MEMORY_CONSTRAINT. * genpreds.c (struct constraint_data): Add is_special_memory. (have_special_memory_constraints, special_memory_start): New static vars. (special_memory_end): Ditto. (add_constraint): Add new arg is_special_memory. Add code to process its true value. Update have_special_memory_constraints. (process_define_constraint): Pass the new arg. (process_define_register_constraint): Ditto. (choose_enum_order): Process special memory. (write_tm_preds_h): Generate enum const CT_SPECIAL_MEMORY and function insn_extra_special_memory_constraint. (main): Process DEFINE_SPECIAL_MEMORY_CONSTRAINT. * gensupport.c (process_rtx): Process DEFINE_SPECIAL_MEMORY_CONSTRAINT. * ira-costs.c (record_reg_classes): Process CT_SPECIAL_MEMORY. * ira-lives.c (single_reg_class): Use insn_extra_special_memory_constraint. * ira.c (ira_setup_alts): Process CT_SPECIAL_MEMORY. * lra-constraints.c (process_alt_operands): Ditto. (curr_insn_transform): Use insn_extra_special_memory_constraint. * recog.c (asm_operand_ok, preprocess_constraints): Process CT_SPECIAL_MEMORY. * reload.c (find_reloads): Ditto. * rtl.def (DEFINE_SPECIFAL_MEMORY_CONSTRAINT): New. * stmt.c (parse_input_constraint): Use insn_extra_special_memory_constraint. From-SVN: r232993
Diffstat (limited to 'gcc/doc')
-rw-r--r--gcc/doc/md.texi14
1 files changed, 14 insertions, 0 deletions
diff --git a/gcc/doc/md.texi b/gcc/doc/md.texi
index 3c11d19..864824f 100644
--- a/gcc/doc/md.texi
+++ b/gcc/doc/md.texi
@@ -4424,6 +4424,20 @@ The syntax and semantics are otherwise identical to
@code{define_constraint}.
@end deffn
+@deffn {MD Expression} define_special_memory_constraint name docstring exp
+Use this expression for constraints that match a subset of all memory
+operands: that is, @code{reload} can not make them match by reloading
+the address as it is described for @code{define_memory_constraint} or
+such address reload is undesirable with the performance point of view.
+
+For example, @code{define_special_memory_constraint} can be useful if
+specifically aligned memory is necessary or desirable for some insn
+operand.
+
+The syntax and semantics are otherwise identical to
+@code{define_constraint}.
+@end deffn
+
@deffn {MD Expression} define_address_constraint name docstring exp
Use this expression for constraints that match a subset of all address
operands: that is, @code{reload} can make the constraint match by